The present invention relates to the connection together of lengths of pipe, via pipe joints, particularly for use in a system in which the connections must be periodically broken and then reestablished.
Various types of installations employ piping containing pipe joints which must be repeatedly broken and reestablished. This is the case, for example, for vacuum and cryogen delivery and return piping employed in the testing, installation and servicing of SSC-type dipole and quadrupole magnets in cryogenic systems.
It is the current practice to join lengths of pipe together for such installations by TIG or MIG butt welding. After testing of the magnet has been completed, each joint must be cut or ground to break the connection. If a magnet installed in an accelerator tunnel must be serviced, the pipe connections must be broken and subsequently reconnected. The required butt welding operation is a time consuming procedure.
Each cutting procedure for breaking a connection must be carried out under carefully controlled conditions to prevent contaminants and debris resulting from the cutting operation from being conveyed to the magnet.
In situations where large diameter piping is employed for such purposes, the connection must be capable of withstanding substantial longitudinal forces associated with leak testing of the welded joint. The forces generated by conventional leak tests are sufficient to break posts supporting the pipeline.